Year	% gross
1970	0.48089000582695
1971	0.598720014095306
1972	0.625680029392242
1973	0.642359972000122
1974	1.25317001342773
1975	2.15086007118225
1976	2.14668011665344
1977	2.6712601184845
1979	2.72912001609802
1980	3.5351300239563
1981	3.08824992179871
1984	4.71527004241943
1985	4.28206014633179
1986	3.81252002716064
1987	3.57255005836487
1988	4.27695989608765
1990	3.92051005363464
1991	3.74640011787415
1992	3.34690999984741
1993	4.42968988418579
1996	5.94377994537354
1999	4.58638000488281
2000	4.29602003097534
2002	4.42417001724243
2004	5.32836008071899
2005	4.68316984176636
2006	4.45237016677856
2011	6.76452016830444
2013	6.17659997940063